Vesicoureteral reflux (VUR), or the reversed flow of urine from the bladder back up into the kidney, is a common pediatric condition, which is present in up to 10% of all children in the United States. In the setting of urinary tract infectio, VUR can be present in up to 50% of otherwise healthy children. In these children, VUR increases the risk of renal scarring, hypertension, proteinuria, and, in extreme cases, end-stage renal disease. Although it is clear that VUR-related, long-term renal problems have a significant impact on affected children, there are children who suffer no VUR-related consequences whatsoever. Unfortunately, VUR research has to date been unable to identify which children are most at risk of VUR-related renal damage. This lack of risk stratification has led to tremendous variation in VUR management: some physicians treat VUR with surgery, others with endoscopy, and others with long-term antibiotics. It remains unclear which of these approaches works best for which children. My long-term career goal is to improve the health of children with VUR and other urological conditions by the application of health services research methods. As a pediatric urologist and a health services researcher, I am in the process of establishing an independent research career in a field where health services research has not yet reached its full potential. Pediatric urology is a subspecialty in the midst of a fundamental shift in its approach to clinical research. My predecessors laid the foundations for urologic research based primarily on their personal clinical and surgical experience; my peers have begun to shift to research based on large-scale observational studies and randomized trials. I plan to contribute to this transformation by introducing comparative effectiveness methodology to the field. My short-term goals are: (1) To further develop my knowledge of techniques and methodologies for comparative-effectiveness research using tools such as observational and administrative databases; (2) to learn and apply the techniques of decision analysis in order to guide clinical decision-making in children with VUR and to support guideline development for VUR treatments; and (3) to develop the foundation for future clinical research of VUR and for future independent funding proposals for this research. To facilitate these goals, I will use the strengths of comparative-effectiveness research to determine which children with VUR will benefit most from which treatment. In Aim 1a, we will use a national database to define the incidence of critical clinical outcomes, such as the incidence of urinary infections after VUR treatment. In Aim 1b, we will validate those findings in a second national database to ensure that our findings are broadly applicable to children with varying disease severity and socioeconomic backgrounds. In Aim 2, we will survey community members to determine patient- and community-based VUR treatment preferences. In the long term, these projects will form the basis for a subsequent R01 application focused on VUR. In the next 5 years I will develop the research expertise and infrastructure to support an active clinical and health services research program, and I will focus that expertise and infrastructure on the most common and most clinically significant conditions in pediatric urology.